The present invention relates to an electrophotographic copying machine wherein a machine body is constructed to be separated into two sections for removing a jammed paper.
The present invention relates more particularly to a light memory removing system in an electrophotographic copying machine, the light memory being produced when the machine body is separated into two sections for removing a jammed paper.
In a conventional electrophotographic copying machine, it was difficult to remove jammed paper or to repair the machine because the operator must remove the jammed paper or secure elements through a thin clearance formed around a photosensitive drum. In order to facilitate the removal of the jammed paper and the repair operation, an electrophotographic copying machine has been proposed, wherein a machine body is constructed to be separated into two sections along a path of copy paper. However, in such a copying machine, a portion of the photosensitive drum is exposed to ambient light when the machine body is separated into two sections. This exposure creates a light memory on the photosensitive drum. The thus created light memory influences the following copying operation. This is because the electric charge is not sufficiently disposed on the photosensitive drum where the light memory is created.
Accordingly, an object of the present invention is to provide an electrophotographic copying machine which ensures a clean copying operation.
Another object of the present invention is to improve an electrophotographic copying machine wherein a machine body is constructed to be separated into two sections along a path of copy paper.
Still another object of the present invention is to provide a light memory removing system in an electrophotographic copying machine wherein a machine body is constructed to be separated into two sections along the path of the copy paper.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a light memory removing system is activated when the machine body is closed after it is separated into two sections along the path of the copy paper. The light memory removing system functions to energize at least a transcription unit and an erase unit without energizing a copy paper transfer system, thereby minimizing the light memory created on the photosensitive drum before initiating an actual copying operation.
In a preferred form, a light memory removing system is activated when a thermal fixing unit reaches a preselected temperature slightly less than the operating temperature. The light memory removing operation is conducted for a period during which the photosensitive drum rotates four (4) revolutions. When the light memory removing operation is completed, the thermal fixing unit reaches the operating temperature.